Synthesis and Characterization of Polyaniline/Magnetite Nanocomposite

A conducting-electroactive polyaniline/magnetite (PAni/Fe304) nanocomposite was synthesized using anilinium dodecylbenzene sulfonate (S1) as a reactive surfactant. First, S1 allowed magnetite dispersion in the aqueous phase and second, S1 performed as the monomer of polyaniline emeraldine base salt. Electron microscopy suggested core-shell morphology based on S1 amphiphilic character; that is, S1 adsorbed onto the magnetite nanoparticles surface and then was polymerized via an oxidative polymerization forming the shell. The PAni/Fe304 composite exhibited improved thermal stability regarding pure PAni, which was related to the strong interaction between PAni and magnetite. Electrical conductivity, determined by the four-probe method, was in the order of 10-1 and 10-3 S cm-1, respectively, for the pure PAni and the composite. Concerning composite magnetic properties, the decrement in magnetization (σr) and hysteresis (Hc) was attributed to the increment in dipolar magnetic interaction due to the increased separation among magnetite nanoparticles because of the PAni shell.